Of course, you can't blame Garnett for this.
Would you expect Garnett to tell his boss, "Hey guy, I don't want $120 million, just give me $40 million as a token. Why are you giving me so much money? Couldn't you save it to wipe your ass? Later on, you could draft Ginobili, Parker, then hit the free market and pick up low-salary guys like Bowen, Jackson, and we could win the championship. Oh, and don't mess with fishy contracts; we could get fined our draft picks."
Look, it's just unreasonable to criticize Garnett's massive contract in hindsight.
There's nothing wrong with players earning high salaries, and there are ways to make room in the salary cap. The real issue is, KG needed the type of player who could handle the ball and take over the offense at crucial moments, a top-tier isolation player.
And there are only a few of those in the entire league; it's even less likely for the Timberwolves, with little to trade, to get one.